Aquatic Sciences Meeting, Albuquerque 2001

Ripley, B, J, University of San Diego, San Diego, USA, bripley@alum.mit.edu

Simovich, M, A, University of San Diego, San Diego, USA, simo@acusd.edu

LIFE HISTORY OF THE SAN DIEGO FAIRY SHRIMP BRANCHINECTA SANDIEGONENSIS: RELATIONSHIP BETWEEN FECUNDITY AND GROWTH UNDER DIFFERENT TEMPERATURE REGIMES

The endangered anostracan Branchinecta sandiegonensis is a common inhabitant of San Diego vernal pools. Although 95% of their habitat has been lost and understanding the basic biology is crucial to management of the remaining habitat, there are few data available on the vital rates of the species. Since annual variability in rainfall and temperature is a defining feature of anostracan habitat, this study addresses the role of different temperature regimes and pool filling times on the survival and reproduction of B. sandiegonensis. In this preliminary study, body length, clutch sizes and egg sizes (for each clutch if more than one were produced) for one temperature regime (23-27C) were measured daily. A positive correlation was found between female longevity and lifetime cyst production, but no relationship existed between female body length and clutch size. This study also showed that males lived for 11.1+/-0.6 days; female longevity was 8.2+/-0.9 days. Results from this experiment will be applied to predictive models for population growth and persistence, which will be used for making management decisions to protect this species and restore its habitat.